The chart shows data for four heat engines.

A 3 column table with 4 rows. The first column is labeled heat engine with entries W, X, Y, Z. The second column is labeled T Subscript h Baseline in Kelvin with entries 620, 840, 900, 500. The last column is labeled T Subscript c Baseline in Kelvin with entries 120, 100, 300, 25.

Which lists the engines from most efficient to least efficient?

Y, X, W, Z
Z, W, X, Y
Z, X, W, Y
Y, W, X, Z

Two kilograms of air within a piston–cylinder assembly executes a carnot power cycle with maximum and minimum temperatures of 800 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assume the ideal gas model for the air. determine the thermal efficiency, the volume at the beginning of the isothermal expansion, in m3, and the work during the adiabatic expansion, in kj.